Reagent card alignment system and method

ABSTRACT

A reagent analyzer and method is described. In the method, a reagent card having a reagent pad is passed through an optical signal path between an optical signal source and an optical signal detector. A transition between a first electrical signal and a second electrical signal is detected to determine a substantially exact position of a leading end or a trailing end of the reagent pad. The first electrical signal is indicative of the substrate interfering with the optical signal. The second electrical signal is indicative of the substrate and reagent pad of the reagent card interfering with the optical signal. The reagent pad is moved to a known second location upon determining the substantially exact position of at least one of the leading end and the trailing end of the reagent pad. At the second location a sample is dispensed onto the reagent pad by a sample dispenser.

INCORPORATION BY REFERENCE

The entirety of the patent application identified by U.S. Ser. No.14/364,778, filed on Jun. 12, 2014; and U.S. Provisional ApplicationSer. No. 61/576,503, filed on Dec. 16, 2011, are hereby expresslyincorporated herein by reference.

BACKGROUND 1. Field of Inventive Concepts

The inventive concepts disclosed herein generally relate to non-contactposition detection and more particularly, but not by way of limitationto optical position detection and analysis of reagent test pads formedical diagnostics via a reagent card alignment system.

2. Brief Description of Related Art

Reagent test strips are widely used in the fields of medicine andclinical chemistry. A test strip usually has one or more test areas, andeach test area is capable of undergoing a color change in response tocontact with a liquid specimen. The liquid specimen usually contains oneor more constituents, substances, or properties of interest. Thepresence and concentrations of these constituents of interest in thespecimen are determinable by an analysis of the color changes undergoneby the test strip. Usually, this analysis involves a color comparisonbetween the test area or test pad and a color standard or scale. In thisway, reagent test strips assist physicians in diagnosing diseases andother health problems.

To satisfy the needs of the medical profession, as well as otherexpanding technologies, such as the brewing industry, chemicalmanufacturing, etc., a myriad of analytical procedures, compositions,and tools have been developed, including the so-called “dip-and-read”type reagent test devices. Regardless of whether dip-and-read testdevices are used for the analysis of a biological fluid or tissue, orfor the analysis of a commercial or industrial fluid or substance, thegeneral procedure involves a test device coming in contact with thesample or specimen to be tested, and manually or instrumentallyanalyzing the test device.

Testing tools and methods have been sought in the art for economicallyand rapidly conducting multiple tests, especially via using automatedprocessing. Automated analyzer systems have an advantage with respect tocost per test, test handling volumes, and/or speed of obtaining testresults or other information over manual testing.

A recent development is the introduction of multiple-profile reagentcards and multiple-profile reagent card automated analyzers.Multiple-profile reagent cards are essentially card-shaped test deviceswhich include a substrate and multiple reagent-impregnated pads (ormatrices) positioned onto the substrate, for simultaneously orsequentially performing multiple analyses of analytes, such as the onedescribed in U.S. Pat. No. 4,526,753, for example, the entire disclosureof which is hereby expressly incorporated herein by reference.

Multiple-profile reagent cards result in an efficient, economical,rapid, and convenient way of performing automated analyses. Automatedanalyzers configured to use multiple-profile reagent cards typicallytake a multiple-profile reagent card, such as from a storage drawer, ora cassette, and advance the multiple-profile reagent card through theanalyzer over a travel surface via a card moving mechanism. The cardmoving mechanism may be a conveyor belt, a ratchet mechanism, a slidingramp, or a card-gripping or pulling mechanism, for example. As themultiple-profile reagent card is moved or travels along the travelsurface, one or more sample dispensers (e.g., manual or automaticpipette or pipette boom) may deposit or dispense one or more samples orreagents onto one or more of the reagent pads. Next, themultiple-profile reagent card may be analyzed (e.g., manually orautomatically) to gauge the test result, such as via an optical imagingsystem, a microscope, or a spectrometer, for example. Finally, the usedreagent card is removed from the analyzer, and is discarded or disposedof in an appropriate manner.

During the manufacturing of multiple-profile reagent cards, the reagentpads are generally attached in rows (e.g., to form one or more teststrips) onto the substrate of the reagent card. However, typicalmanufacturing tolerances allow for a possible variance of about 2 mm ofthe positions of the rows of reagent pads relative to the substrate ofthe reagent card, with adjacent rows of reagent pads typically beingseparated by about 5 mm from one another.

Further, as reagent pads are generally rectangular in shape, it isoptimal to deposit the sample substantially at the center of a reagentpad or at a central region of the reagent pad to help ensure thoroughsaturation of the reagent pad with sample, and to substantially preventthe sample from leaking out of the reagent pad and onto the substrate ofthe reagent card or into adjacent reagent pads.

Due to the need to precisely dispense the sample onto the reagent padand the fact that reagent pad positions on the reagent card haverelatively large manufacturing tolerances, it is important for automatedanalyzers to precisely locate the reagent pad on the multiple-profilereagent card prior to depositing the sample thereon.

Multiple prior art systems have attempted to resolve this problemwithout success. Several such systems are contact systems, which arecomplicated and inaccurate, and may cause misfeeding of reagent cards ordamage to the reagent cards or reagent pads by contacting them.

To that end, a need exists in the prior art for a non-contact opticalmethod and alignment system for precisely determining the positions ofreagent cards and of one or more reagent pads on the reagent cards. Itis to such optical card alignment systems and methods that the inventiveconcepts disclosed herein are directed.

SUMMARY

In one aspect the inventive concepts disclosed herein are directed to areagent card analyzer comprising an optical signal source configured totransmit an optical signal having a strength and an optical signaldetector spaced a distance from the optical signal source so that theoptical signal source and the optical signal detector cooperate todefine an optical signal path into which the optical signal sourcetransmits the optical signal. The optical signal detector is configuredto detect the optical signal and to output an electrical signalindicative of the strength of the optical signal. A reader is configuredto read a reagent pad of a reagent card. A reagent card moving mechanismis configured to move one or more reagent card having the reagent padincluding a leading end and a trailing end through the optical signalpath and toward the reader. An optical detector interface iselectrically coupled with the optical signal detector and is configuredto receive electrical signals from the optical signal detector and tooutput a pad detect signal indicative of at least one of the leading endand the trailing end of the reagent pad as the reagent card is movedthrough the optical signal path.

The optical signal path may be at a first location, and a sampledispenser configured to dispense a volume of a sample may be positionedat a second location separated a known distance from the first location.The card moving mechanism may be configured to move the one or morereagent card so that the one or more reagent pad is positionedsubstantially at the second location based upon the pad detect signal.In some exemplary embodiments the one or more reagent pad may have acentral region, and the sample dispenser may be configured to dispense avolume of a sample on the central region of the one or more reagent pad.The reader may include an imaging system configured to capture an imageof the one or more reagent pad at a third location separated at a knowndistance from the first location. The card moving mechanism may beconfigured to move the one or more reagent card so that the one or morereagent pad is positioned substantially at the third location based uponthe pad detect signal. The optical signal may have a wavelength of about850 nanometers. The optical signal source may include a vertical cavitysurface emitting laser. The vertical cavity surface emitting laser maybe configured to transmit an optical signal including a beam having anangular spread of less than about 2°.

In another aspect, the inventive concepts disclosed herein are directedto a reagent card analyzer comprising an optical signal source attachedto a support and configured to transmit an optical signal having astrength and an optical signal detector attached to the support andspaced at a distance from the optical signal source so that the opticalsignal source and the optical signal detector cooperate to define anoptical signal path at a first location, the optical signal detectorconfigured to detect the optical signal and to generate an electricalsignal indicative of the optical signal. A reader is configured to readone or more reagent pad of a reagent card positioned at a secondlocation a known distance from the first location. A sample dispenser isconfigured to dispense a volume of sample on the one or more reagent padof the reagent card and is positioned at a third location. A card movingmechanism is configured to move the reagent card between the opticalsignal source and the optical signal detector so that the reagent cardinterferes with the optical signal, and to move the reagent card so asto position the one or more reagent pad substantially at the second andthe third location. An optical detector interface is electricallycoupled to the optical signal detector and is configured to receiveelectrical signals from the optical signal detector and to output a paddetect signal indicative of at least one of the leading end and thetrailing end of the reagent pad as the reagent card is moved between theoptical signal source and the optical signal detector. A controller isconfigured to control the reader, the sample dispenser, and the andmoving mechanism, the controller electrically coupled with the opticaldetector interface, wherein the controller is configured to operate thecard moving mechanism to move the one or more reagent card so that theone or more reagent pad is positioned substantially at the secondlocation or substantially at the third location based upon the paddetect signal.

The one or more reagent pad may have a central region, and the sampledispenser may be configured to dispense a volume of a sample on thecentral region of the one or more reagent pad. The reader may include animaging system configured to capture an image of the one or more reagentpad at the third location. The optical signal may have a wavelength ofabout 850 nanometers. The optical signal source may include a verticalcavity surface emitting laser. The vertical cavity surface emittinglaser may be configured to transmit an optical signal including a beamhaving an angular spread of less than about 2°.

In yet another aspect, the inventive concepts disclosed herein aredirected to a method comprising passing a reagent card having a sequenceof reagent pads including leading and trailing ends through an opticalsignal path defined by an optical signal source and an optical signaldetector spaced at a distance from one another. The method furthercomprises receiving an electrical signal from the optical signaldetector by an optical detector interface electrically coupled to theoptical signal detector and configured to receive electrical signalsfrom the optical signal detector. The method also comprises outputting asequence of pad detect signals indicative of at least one of the leadingend and the trailing end of the sequence of reagent pads as the reagentcard is moved through the optical signal path.

In yet another aspect, the inventive concepts disclosed herein aredirected to a method comprising attaching an optical signal source andan optical signal detector to a support of an analyzer upstream of asample dispenser to direct an optical signal across a predetermined cardtravel path within the analyzer, and coupling an optical detectorinterface to the optical signal detector and a controller of theanalyzer, the optical detector interface configured to receiveelectrical signals from the optical signal detector and to output a paddetect signal indicative of at least one of a leading end and a trailingend of a reagent pad to the controller as a reagent card is movedbetween the optical signal source and the optical signal detector.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the inventive concepts disclosed herein may be betterunderstood when consideration is given to the following detaileddescription thereof. Such description makes reference to the annexedpictorial illustrations, schematics, graphs, figures, or drawings. Thedrawings are not necessarily to scale, and certain features and certainviews of the drawings may be shown exaggerated, to scale, or inschematic in the interest of clarity and conciseness. Like referencenumerals in the figures may represent and refer to the same or similarelement or function. In the drawings:

FIG. 1 is a perspective view of an exemplary embodiment of a cardanalyzer according to the inventive concepts disclosed herein with anexternal housing not shown for clarity.

FIG. 2 is a perspective view of the card analyzer of FIG. 1, showing anexemplary embodiment of a card alignment system according to theinventive concepts disclosed herein.

FIG. 3 is a partial perspective view of the card analyzer of FIG. 1,showing the card alignment system.

FIG. 4 is another partial perspective view of an exemplary embodiment ofthe card alignment system of FIG. 3.

FIG. 5 is a perspective view of the card alignment system of FIG. 3.

FIG. 6 is a diagram of an exemplary embodiment of a controller for thecard alignment system according to the inventive concepts disclosedherein.

FIG. 7 is a graph showing an electrical sign processed by a signalcomparator circuit according to the inventive concepts disclosed herein.

FIG. 8 is a partial perspective view of an analyzer according to theinventive concepts disclosed herein, with an edge of the card positionedbetween an optical signal source and an optical signal detector of acard alignment system thereof.

FIG. 9 is a partial perspective view of the analyzer of FIG. 8 with aleading end of a pad shown positioned between the optical signal sourceand the optical signal detector of a card alignment system thereof.

FIG. 10 is a partial perspective view of the analyzer of FIG. 8, showingthe reagent card advanced along the travel surface and a sample beingdispensed onto one of the reagent pads thereof.

DETAILED DESCRIPTION

Before explaining at least one embodiment of the inventive conceptsdisclosed herein in detail, it is to be understood that the inventiveconcepts are not limited in their application to the details ofconstruction and the arrangement of the components or steps ormethodologies set forth in the following description or illustrated inthe drawings. The inventive concepts disclosed herein are capable ofother embodiments or of being practiced or carried out in various ways.Also, it is to be understood that the phraseology and terminologyemployed herein is for the purpose of description and should not beregarded as limiting the inventive concepts disclosed and claimed hereinin any way.

In the following detailed description of embodiments of the inventiveconcepts, numerous specific details are set forth in order to provide amore thorough understanding of the inventive concepts. However, it willbe apparent to one of ordinary skill in the art that the inventiveconcepts within the disclosure may be practiced without these specificdetails. In other instances, well-known features have not been describedin detail to avoid unnecessarily complicating the instant disclosure.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherently present therein.

Unless expressly stated to the contrary, “or” refers to an inclusive orand not to an exclusive or. For example, a condition A or B is satisfiedby anyone of the following: A is true (or present) and B is false (ornot present), A is false (or not present) and B is true (or present),and both A and B are true (or present).

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the inventive concepts. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Further, as used herein any reference to “one embodiment” or “anembodiment” means that a particular element, feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment.

Finally, as used herein qualifiers such as “about,” “approximately,” and“substantially” are intended to signify that the item being qualified isnot limited to the exact value specified, but includes some slightvariations or deviations therefrom, caused by measuring error,manufacturing tolerances, stress exerted on various parts, wear andtear, and combinations thereof, for example.

The inventive concepts disclosed herein are generally directed tomedical diagnostic systems, and more particularly, but not by way oflimitation, to non-contact reagent card alignment systems and methodsfor making and using automated multiple-profile reagent card analyzers.In some exemplary embodiments of the inventive concepts disclosedherein, a non-contact method and system is disclosed to determinesubstantially exactly (within about less than 0.2 mm) the location of anedge of a substrate of a multiple-profile reagent card (hereinafter“reagent card,” or “card”) and the location of the ends of one or morereagent pads attached to the substrate of the reagent card.

The inventive concepts disclosed herein may employ an optical signal(e.g., a laser) based method to determine the positions of the edges ofthe substrate of the reagent cards and the ends of the reagent pads. Forexample, an optical signal source may be positioned above a surface onwhich a reagent card travels or is advanced, and an optical signaldetector may be positioned below the surface of which the reagent cardtravels, such that the reagent card may be advanced along the surfaceand positioned between the optical signal source and the optical signaldetector. The optical signal source may emit or transmit an opticalsignal which may be detected by the optical signal detector. When noreagent card is positioned between the optical signal source and theoptical signal detector, the optical signal detected by the opticalsignal detector would be relatively strong, as there may only be airinterfering with the optical signal as it travels between the opticalsignal source and the optical signal detector. The optical signaldetector may detect the relatively strong optical signal and maygenerate a first electrical signal that is relatively strong andindicative of the relatively strong optical signal. The first electricalsignal may be transmitted to an optical detector interface, as will bedescribed below.

As a leading edge of a reagent card is advanced along the travel surfaceand is positioned at least partially between the optical signal sourceand the optical signal detector, the substrate of the reagent cardbegins interfering with the optical signal emitted by the optical signalsource, causing a drop in the strength of the optical signal thatreaches the optical signal detector. The substrate may be translucentplastic or other material that behaves as an optical diffuser, diffusingthe optical signal between the optical signal source and the opticalsignal detector, for example. In response, the optical signal detectordetects an optical signal which is relatively weaker compared to therelatively strong signal received when no card is present between theoptical signal source and the optical signal detector. The opticalsignal detector may generate a second electrical signal that isrelatively weaker and indicative of the relatively weaker opticalsignal. The optical signal detector may transmit the second electricalsignal to an optical detector interface, for example.

As the reagent card is further advanced along the travel surface, aleading end of a reagent pad is positioned at least partially betweenthe optical signal source and the optical signal detector and thereagent pad begins further interfering with the optical signal emittedby the optical signal source and causes a further drop in the strengthof the optical signal that reaches the optical signal detector. Theoptical signal detector detects this relatively weaker optical signaland generates a third electrical signal indicative of the relativelyweaker optical signal. The optical signal detector may transmit thethird electrical signal to the optical detector interface, for example.

The difference between the second electrical signal and the thirdelectrical signal may be very small, so the second electrical signal andthe third electrical signal may be amplified, offset, or otherwiseprocessed by the optical detector interface as will be described below,for example, to provide information indicative of which part of thereagent card, if any is positioned between the optical signal source andthe optical signal detector.

The optical detector interface circuit may offset the incoming first,second, and third electrical signals by subtracting the range below thelowest measured signal from the received signal, and amplifying theresulting signal (e.g., about 2.5 times) to produce a processed signalindicative of the portion of a reagent card, if any, which is currentlyinterfering with the optical signal, for example.

The substantially exact position of the leading edge of the substrate ofthe reagent card, and of the leading ends and trailing ends of thereagents pads may thus be detected and/or determined, and thisinformation may be combined with the known location of a sampledispenser to operate the mechanism that advances the reagent card tosubstantially center the reagent pad under the sample dispenser byadvancing the reagent card a certain distance over the travel surface,for example. A sample may be dispensed onto a central region of one ormore reagent pad, for example. This information can also be combinedwith the known location of an imaging system, so that the reagent cardmay be advanced to any desired location or designated target area withina field of view of the imaging system, and one or more images of thereagent card and/or of the reagent pads may be captured by the imagingsystem, for example.

In one aspect, the inventive concepts disclosed herein, are directed toa card positioning system for an automated analyzer instrument thatutilizes disposable multiple-profile reagent cards which have asubstrate and a matrix of pads impregnated with various reagentspositioned on a surface of the substrate. The reagent card and pads canbe precisely aligned in order to dispense samples onto central regionsof the pads for optimal sample distribution. In one example, the padsare bonded to the card with a possible variance of about 2 mm. Anonboard optical system or other imaging system may then take digitalpictures of the rows of pads, for example. The optical system may beconfigured as a medical diagnostic device that reads reagent cards, forexample. The reagent cards may be stored in a stack or in a cassette ina reagent box, and may be incrementally advanced one reagent card at atime past a moisture protection gate. Once past the gate, bodily fluidsamples such as urine may be deposited on each of the pads on thereagent card by a sample dispenser such as a pipette boom, for example.The analyzer may then advance the card to a target area to be imaged bythe optical system.

In order for appropriate readings to be taken by the optical system, thedevice may determine and confirm the placement of the cards and thepads. In order to accomplish this, the device may be equipped with acard alignment system including an optical signal source such as alaser, and an optical signal detector that utilizes the differences inabsorbance light levels between three different conditions of cardmovement. The detector may sense no card (zero absorbance), card edge orsubstrate (between about 99.90% and about 99.99% absorbance), and padends (an additional 30% on top of the 99.90% to 99.99% absorbance), forexample. The optical properties of the card substrate may vary between afirst lot of card substrate and a second lot of card substrate, and thecard alignment system may be calibrated to each first card of a new lotor each new cassette as will be described below. The optical signalsource may incorporate a special type of laser diode called a VCSELwhich stands for Vertical Cavity Surface Emitting Laser, in someexemplary embodiments. This optical signal source may operate at aninvisible wavelength of 850 nanometers and may possess a unique propertyof producing a narrow (e.g., less than about 2°) cylindrical beam whichis very useful for making position measurements, for example. Theoptical signal source and optical signal detector may be placed aboveand below the reagent card travel surface to take appropriate readingsin some exemplary embodiments.

Referring now to FIGS. 1-2, shown therein is a perspective view of anexemplary embodiment of an automatic analyzer 100 according to theinventive concepts disclosed herein. The analyzer 100 may include astorage compartment assembly 102 configured to accept a reagent cardcassette 104 having one or more reagent cards 106 therein, a card travelassembly 108 configured to move a multiple-profile reagent card 106along a travel surface 110 past a sample delivery assembly 112, and animaging system 114, for example.

The storage compartment assembly 102 may include a storage compartment116, a gate assembly 118, a card-stripping assembly 120, and a cardalignment system 122, for example.

The storage compartment 116 may be implemented as any suitable housingconfigured to receive and store one or more reagent cards 106 therein,such that the one or more reagent cards 106 may be stripped or removedfrom the storage compartment 116 one at a time and may be advanced overthe travel surface 110 as will be described below. The storagecompartment 116 may be configured to receive and hold a stack of reagentcards 106 therein, or may be configured to receive a cartridge or acassette 104 containing one or more reagent cards 106 therein, forexample.

The storage compartment 116 may include a door 124 and a bottom 126. Thedoor 124 may be implemented as any member that may be selectively openedand closed to allow access to the storage compartment 116 so that one ormore reagent cards 106 or the cassette 104 may be introduced into orremoved from the storage compartment 116. In some exemplary embodimentsof the inventive concepts disclosed herein, the storage compartment 116and the door 124 may be substantially vapor-tight, so as to protect anyreagent cards 106 positioned inside the storage compartment 116 fromvapors, moisture, or other contamination, as will be readily appreciatedby a person of ordinary skill in the art having the benefit of theinstant disclosure. Further, when the door 124 and a gate of the gateassembly 118 are substantially closed, the storage compartment 116 maybe substantially opaque to light in the visible range, such thatsubstantially no light in the visible range enter or exit the storagecompartment 116, for example. Further, in some exemplary embodiments thestorage compartment 116 may be substantially opaque to optical signalsin the non-visible range, so that substantially no optical signals inthe non-visible range may enter or exit the storage compartment 116.

The bottom 126 may be implemented as any suitable member, and may atleast partially define the travel surface 110, as will be appreciated bypersons of ordinary skill in the art having the benefit of the instantdisclosure.

The gate assembly 118 may include a gate 128 operably coupled with agate raising mechanism 130, for example. The gate 128 is shown asforming a part of the storage compartment 116, such that the gate 128may be selectively opened and closed by the gate raising mechanism 130to allow one or more reagent cards 106 to be advanced out of the storagecompartment 116 and over the travel surface 110. In some exemplaryembodiments, the gate 128 may also be configured as a vapor or moisturebarrier, protecting the inside of the storage compartment 116 frommoisture and contamination, for example. Further, the gate 128 mayoperate as a light barrier, such that substantially no light in thevisible or optical signals in the non-visible range may enter or exitthe storage compartment 116 when the gate 128 is substantially closed,for example.

The gate 128 may be operated by any suitable gate raising mechanism,such as the gate raising mechanism 130, which may be manual orautomatic, and may include a gear mechanism, a servo, an electricalmotor, an actuator, and combinations thereof, for example. In someexemplary embodiments a computer processor (not shown) executingprocessor executable code may operate the gate raising mechanism 130 toraise and lower the gate 128, and to operate the card-stripping assembly120 to advance one or more reagent cards 106 partially or substantiallycompletely past the gate 128 and onto the travel surface 110.

The card-stripping assembly 120 may extend at least partially into thestorage compartment 116, and may be configured to strip, eject, advance,or otherwise remove a reagent card 106 from the storage compartment 116(e.g., from a cassette 104 or from a stack of reagent cards 106), andadvance such reagent card 106 at least partially past the gate 128, forexample.

In some exemplary embodiments, the card-stripping assembly 120 may beconfigured to advance one or more reagent card 106 out of the storagecompartment 116 and at least partially or substantially completely pastthe gate 128, when the gate 128 is partially or completely raised oropen. In some exemplary embodiments, the gate 128 may be lowered ontothe reagent card 106 as the reagent card 106 is partially advanced outof the storage compartment 116.

The card-stripping assembly 120 may include any suitable mechanism suchas a conveyor belt, or a movable plate 132 having a card-strippingprotrusion 134 formed therein, and combinations thereof, for example.The movable plate 132 may be moved along or adjacent to the bottom 126of the storage compartment 116, such that the card-stripping protrusion134 may engage with a trailing edge of a reagent card 106 and advancethe reagent card 106 towards the gate 128 and at least partially past orbeyond the gate 128 when the gate 128 is open or raised. As will beappreciated by persons of ordinary skill in the art, the movable plate132 may be moved by any suitable moving mechanism, including a motor, acarriage, a servo, an actuator, or combinations thereof, for example.The moving mechanism may be configured to move the movable plate 132along or adjacent to the bottom 126, for example.

It is to be understood that in some exemplary embodiments of theinventive concepts disclosed herein, the card-stripping assembly 120 maybe omitted and one or more reagent card 106 may be advanced past thegate 128 in any desired manner, such as via gravity, conveyor belt,spring-loaded ejection mechanism, a ratchet mechanism, manually, andcombinations thereof. Further, in some exemplary embodiments of theinventive concepts disclosed herein the storage compartment 116 may beomitted, and one or more reagent card 106 may be introduced onto thetravel surface 110 in any suitable manner, including being manuallyinserted or fed into the analyzer 100, being provided in a roll, orcombinations thereof.

The one or more reagent card 106 may include a substrate 135 with aleading edge 136, a trailing edge 138, and may have one or more reagentpads 140 positioned thereon, such that the one or more reagent pads 140are aligned to define a test strip 142. As can be seen in FIG. 2, thereagent pads 140 may have a leading end 144 and a trailing end 146, andmay be spaced apart a distance from one another.

Referring now to FIGS. 3-5, the card alignment system 122 may include anoptical signal source 150 supported by a housing 152 which may beconnected to the gate 128, and an optical signal detector 154 housed ina base 156 supported by the bottom 126 of the card storage compartment116 so that the optical signal source 150 and the optical signaldetector 154 are spaced a distance from one another, and so that theoptical signal detector 154 is positioned at or below the travel surface110, and the optical signal source 150 is positioned above the travelsurface 110, or vice-versa, for example. The optical signal source 150and the optical signal detector 154 may be aligned with one another soas to cooperate to define an optical signal path 158 (FIG. 5)therebetween, for example.

It is to be understood that in some exemplary embodiments of theinventive concepts disclosed herein, the optical signal source 150 maybe supported by the bottom 126, and the optical signal detector 154 maybe connected to the gate 128, as will be readily appreciated by a personof ordinary skill in the art. Further, it should be understood that insome exemplary embodiments, the optical signal source 150 and theoptical signal detector 154 may be supported above and below the travelsurface 110 to define the optical signal path 158 in any desired manner,such as by being connected to, or supported by any desired components orstructure of the analyzer 100, provided that the reagent card 106 is atleast partially positionable in the optical signal path 158 as thereagent card 106 is advanced towards the gate 128, past the gate 128,and/or along the travel surface 110, for example.

The optical signal source 150 may be implemented as any suitable deviceconfigured to emit or transmit an optical signal, such as a verticalcavity surface emitting laser, for example. The optical signal source150 may be configured to emit an optical signal including a relativelynarrow optical beam (e.g., having a relatively narrow angular spread ofless than about 2°), and any desired wavelength such as a wavelength ofabout 850 nM, for example. In some exemplary embodiments of theinventive concepts disclosed herein, the optical signal source 150 mayemit or transmit and optical signal having any desired wavelength, suchas a wavelength varying between about 800 nM and about 900 nM, forexample. It is to be understood that the optical signal source 150 maybe implemented as any suitable device such as a light emitting diode, alaser, a quantum-well emitter, and may have any wavelength, including anadjustable wavelength and a substantially constant wavelength, andcombinations thereof, for example. Further, the optical signal source150 may emit any desired size optical beam, having an angular spreadvarying between about 0° to about 5°, or more, for example. As will berecognized by persons of ordinary skill in the art, the accuracy andprecision of the card alignment system increases as the width and/or theangular spread of the optical beam emitted by the optical signal source150 is reduced.

The optical signal source 150 may be attached to the housing 152 in anysuitable manner, such as by adhesives, welds bolts, seams, joints, andcombinations thereof, for example. In some exemplary embodiments, theoptical signal source 150 and the housing 152 may be implemented as aunitary body, while in some exemplary embodiments the housing 152 may beomitted and the optical signal source 150 may be directly attached tothe gate 128, or to any other desired component of the analyzer 100.

The housing 152 may likewise be attached to the gate 128 in any desiredmanner. An optional electrical connector 160 (FIG. 5) may be implementedas any desirable connector 160 and may be electrically coupled with theoptical signal source 150 and with any suitable power source and/orcontrol signal source (e.g., controller 162, FIG. 6) configured to powerthe optical signal source 150 and to control the strength of intensityof the optical signal emitted by the optical signal source 150, forexample. As will be readily appreciated by a person of ordinary skill inthe art having the benefit of the instant disclosure, it is desirablethat the optical signal source 150 emits an optical signal having arelatively or substantially constant strength or intensity, althoughsuch strength or intensity may be adjustable to calibrate the cardalignment system 122, for example. To that end, a controller 162 (FIG.6) may be operably coupled with the optical signal source 150 and may beconfigured to ensure that the optical signal source 150 emits asubstantially constant optical signal and/or to calibrate the opticalsignal source 150, for example, as will be described below.

As will be appreciated by persons of ordinary skill in the art havingthe benefit of the instant disclosure, the optical signal emitted by theoptical signal source 150 may be processed, conditioned, filtered,diffused, polarized, or otherwise conditioned by one or more lenses (notshown), filters (not shown), collimators (not shown), diffusers (notshown), refractors (not shown), mirrors (not shown), prisms (not shown),and other devices, or combinations thereof, prior to being detected bythe optical signal detector 154, for example.

Further, in some exemplary embodiments of the inventive conceptsdisclosed herein, the optical signal source 150 may be supported abovethe travel surface 110 in any desired manner, such as by being connectedto the gate 128 in any desired manner (e.g., via joints, seams, bolts,brackets, fasteners, welds, or combinations thereof), or by the storagecompartment 116, or by any other desired component of the analyzer 100,for example.

As will be appreciated by persons of ordinary skill in the art, in someexemplary embodiments of the inventive concepts disclosed herein, morethan one optical signal source 150 may be implemented, such as two, ormore than two optical signal sources 150.

An optional roller assembly 164 may be implemented with the housing 152and may have a roller 166 configured to roll along the reagent card 106as the regent card 106 is advanced through the optical signal path 158,so as to ensure that the substrate 135 of the reagent card 106 ismaintained at a controlled distance from the optical signal source 150and/or the optical signal detector 154 as the reagent card 106 travelsinto and through the optical signal path 158, for example. When noreagent card 106 is present between the optical signal source 150 andthe optical signal detector 154, the optional roller assembly 164 maycome into contact with the base 156 of the optical signal detector 154,for example. In some exemplary embodiments of the inventive conceptsdisclosed herein, the roller assembly 164 may be configured to operateas a switch, so that the optical signal source 150 is turned off whenthe roller assembly 164 is not in contact with the base 156 or with areagent card 106, and so that the optical signal source 150 is turned onwhen the roller assembly 164 is in contact with the base 156 or with areagent card 106, for example. The optional roller assembly 164 may beoperably coupled with the controller 162 (FIG. 6), for example.

The optical signal detector 154 may be implemented as any deviceconfigured to detect optical signals and to convert optical signals intoelectrical signals, such as a silicon pin diode detector, charge-coupleddevice, or any other suitable device. The optical signal detector 154 isconfigured to detect an optical signal emitted by the optical signalsource 150 and to generate an electrical signal indicative of thestrength or intensity (or any other qualities, properties, orattributes) of the detected optical signal. For example, in someembodiments the optical signal detector 154 may generate electricalcurrent which is proportional to the intensity or strength of theoptical signal detected by the optical signal detector 154. Desirably,the optical signal detector 154 has a relatively narrow aperture, ordetection area, such as an aperture or detection area of about 1 mm²,for example, to improve a signal-to-noise ratio achieved by the opticalsignal detector 154. It is to be understood that other aperture sizes ordetection areas may be used with the optical signal detector 154,varying from about 0 mm² to about 5 mm², or more, for example.

The optical signal detector 154 may be connected to the bottom 126, viathe base 156, which may be implemented as a suitable support structureconnected to the bottom 126 in any desired manner, such as via screws,adhesives, bolts, joints, seams, brackets, and combinations thereof, forexample. The base 156 may have an upper surface 168 into which theoptical signal detector 154 may be incorporated, for example. In someexemplary embodiments, the optical signal detector 154 may partiallyextend below or above the upper surface 168, as will be appreciated bypersons of ordinary skill in the art. In some exemplary embodiments ofthe inventive concepts disclosed herein, the base 156 may be configuredto allow one or more reagent cards 106 to slide over the base 156 as thereagent card 106 is advanced out of the storage compartment 116.Further, in some exemplary embodiments, the upper surface 168 of thebase 156 may at least partially define the travel surface 110, or may bepositioned substantially level with the travel surface 110 and adjacentthereto.

As will be appreciated by persons of ordinary skill in the art, in someexemplary embodiments, the base 156 may be omitted, or the base 156 andthe bottom 126 may be formed as a unitary body. Further, in someexemplary embodiments of the inventive concepts disclosed herein, morethan one optical signal detector 154 may be implemented, such as two, ormore than two optical signal detectors 154.

The optical signal detector 154 may be operatively coupled with thecontroller 162 (FIG. 6), as will be described below.

Referring back to FIGS. 1-2, the card travel assembly 108 may beconfigured to move the reagent card 106 along the travel surface 110.

The card travel assembly 108 may include a movable card gripper 170configured to move the reagent card 106 along the travel surface 110,such as by gripping the reagent card 106 and sliding, or otherwiseadvancing the reagent card 106 along the travel surface 110, forexample. The card travel assembly 108 may move substantiallylongitudinally relative to the travel surface 110, such as via a movablecarriage, for example. The card gripper 170 may be configured to grip,grasp, or otherwise engage a portion of the reagent card 106 as thereagent card 106 is advanced past the gate 128, for example.

The travel surface 110 may be supported by a base 172 and may beimplemented as a substantially flat surface configured to allow thereagent card 106 to travel thereon, such as via sliding over the travelsurface 110, for example. The travel surface 110 may extendsubstantially horizontally adjacent to the gate 128, such that a reagentcard 106 advanced past the gate 128 may be advanced or otherwise travelover the travel surface 110. In some exemplary embodiments, the travelsurface 110 may extend partially past the gate 128 and into the storagecompartment 116, such that the gate 128 is lowered onto the travelsurface 110, as will be appreciated by persons of ordinary skill in theart having the benefit of the instant disclosure.

The travel surface 110 may be constructed of any suitable material, suchas plastics, metals, non-metals, thermoset materials, glass, resins, andcombinations thereof, for example. The travel surface 110 may beconstructed using any suitable technique such as injection molding,casting, machining, 3D printing, and combinations thereof, for example.

The sample delivery assembly 112 may be implemented as any desiredsystem configured to deliver or dispense a volume of a sample onto areagent pad 140 and/or a reagent card 106, and may include a sampledispenser 174 (e.g., an automated pipette boom, a manual pipette, aport, a syringe, a fluid pump, and combinations thereof). The sampledispenser 174 may be movably supported above the travel surface 110 andoutside the storage compartment 116, so that the sample dispenser 174may move laterally or transversely relative to the travel surface 110along a line 176 for example. The sample dispenser 174 may deliver ordispense a volume of sample along the line 176 on the travel surface110. The line 176 may be referred to as a sample delivery location orline, and a volume of a sample may be delivered or dispensed along anypoint along the line 176 by the sample dispenser 174 when a reagent card106, reagent pad 140, or a test strip 142 is positioned thereon, forexample.

The card alignment system 122 may function in combination with the cardstripper assembly 120 to precisely position one or more reagent pads 140or a test strip 142 on the line 176, so that a volume of sample may bedeposited by the sample dispenser 174 onto the reagent pad 140 or teststrip 142 substantially centered onto the line 176 and below the sampledispenser 174, as will be described in detail below. The sample may bedeposited on a central region of the reagent pad 140, which centralregion may include a center of the reagent pad 140 and a regionincluding or surrounding the center of the reagent pad 140 and extendingaround the center of the reagent pad 140 by between about 0 and about 50percent of the width of the reagent pad 140 (e.g., the distance betweenthe leading end 144 and the trailing end 146 of the reagent pad 140),for example. Depositing a volume of one or more samples substantiallycentered on the one or more reagent pads 140 may ensure that thedeposited sample is substantially absorbed by the one or more reagentpad 140 and does not leak onto the substrate 135 of the reagent card106, to avoid contaminating the reagent card 106 or adjacent reagentpads 140, as will be appreciated by a person of ordinary skill in theart having the benefit of the instant disclosure.

As will be appreciated by persons of ordinary skill in the art, in someexemplary embodiments of the inventive concepts disclosed herein, thesample dispenser 174 may be stationary, and/or two or more sampledispensers 174 may be positioned along the line 176 so that a volume ofsample may be delivered by the two or more sample dispensers 174 to twoor more reagent pads 140 positioned substantially centered on the line176.

The imaging system 114 may be implemented and function as any desiredreader, and may be supported at a location above the travel surface 110,so that an image of the reagent pads 140 may be captured by the imagingsystem 114, for example. The imaging system 114 may take an image of areagent pad 140 at any desired target location or area along the travelsurface 110, including the line 176, or any other desired location orarea or multiple locations or areas, for example. As will be readilyappreciated by a person of ordinary skill in the art, preciselypositioning the reagent pad 140 on the line 176 would also allow theanalyzer 100 to precisely position the reagent pads 140 of the reagentcard 106 on any desired location along the travel surface 110, such thatan image of any desired portion of the reagent card 106 or the reagentpads 140 may be taken by the imaging system 114. In some exemplaryembodiments, the imaging system 114 may take an image of the reagentpads 140 as the reagent pads 140 are positioned onto the line 176, whilein some exemplary embodiments the imaging system 114 may take an imageof the reagent pads 140 as they are advanced past the line 176, andcombinations thereof. Further, the imaging system 114 may take an imageof the reagent pads 140 as the reagent pads 140 are positioned on adesignated target location or area (not referenced) on the travelsurface 110, which designated target location or area may be anylocation or area of the travel surface 110, including the line 176, forexample.

The imaging system 114 may include any desired digital or analog imager,such as a digital camera, an analog camera, a CMOS imager, a diode, andcombinations thereof. The imaging system 114 may also include anydesired illumination source and/or lens system, for example. Further,the imaging system 114 is not limited to an optical imaging system inthe visible spectrum, and may include a microwave imaging system, anX-ray imaging system, and other desired imaging systems, for example.

Referring now to FIGS. 6-7, the analyzer 100 may be provided with anoptical source interface 180, and an optical detector interface 182. Ingeneral, the optical source interface 180 includes analog and/or digitalcircuitry that receives an activation signal from the controller 162 viaa control line 184. Upon receipt of the activation signal from thecontroller 162, the optical source interface 180 generates a controlsignal and supplies the control signal to the optical signal source 150via control lines 186 and 188. In particular, the control signal can beeither a predetermined current signal, or a predetermined voltage signaldepending upon the construction of the optical signal source 150, forexample. In either case, the control signal may be controlled to providea constant magnitude or strength such that the optical signal generatedand emitted by the optical signal source 150 includes a substantiallyfixed and predetermined magnitude or strength, for example. In oneembodiment, the control line 186 provides a predetermined amount ofcurrent to the optical signal source 150 while the control line 188serves as a current sink for the optical signal source 150, for example.Optionally, the controller 162 may be electrically coupled to theoptical source interface 180 via a control line 190 such that thecontroller 162 may supply a reference signal to the optical sourceinterface 180. The reference signal can be used by the optical sourceinterface 180 to set a magnitude of the control signal supplied to theoptical signal source 150.

In general, the optical detector interface 182 may include analog and/ordigital circuitry that receives a signal from the optical signaldetector 154 via a line 194 and interprets the signal to provide a carddetect sensor signal to the controller 162 via a control line 196, and apad detect sensor signal to the controller 162 via a control line 198.The signal received from the optical signal detector 154 is desirably anelectrical signal that has linear properties relative to a magnitude orstrength of the optical signal provided by the optical signal source150. In one embodiment, the optical signal detector 154 is a photodiode.In any event, the signal received from the optical signal detector 154may be an electrical signal whose magnitude is indicative of anintensity or strength of the optical signal received by the opticalsignal detector 154.

In one embodiment, the optical detector interface 182 is provided withan amplifier 200, a card comparator circuit 202, and a pad detectorcircuit 204. The electrical signal generated by the optical signaldetector 154 is fed to the amplifier 200 by the line 194. The amplifier200 receives the electrical signal and amplifies the electrical signalsuch that changes in the electrical signal can be interpreted by thecard comparator circuit 202 to detect the leading and trailing edges 136and 138 of the substrate 135, and interpreted by the pad detectorcircuit 204 to detect the leading and trailing ends 144 and 146 of thereagent pads 140. The amplifier 200 may include an operational amplifierthat is configured to be an inverting current to voltage amplifier.

Shown in FIG. 7 is a waveform 208 indicative of an exemplary output ofthe amplifier 200. As discussed above, the leading edge 136 of thesubstrate 135 is advanced along the travel surface 110 and is positionedat least partially between the optical signal source 150 and the opticalsignal detector 154 (e.g., in the optical signal path 158), thesubstrate 135 of the reagent card 106 begins interfering with theoptical signal, causing a drop in the strength of the optical signalthat reaches the optical signal detector 154. The amplifier 200 may bedesigned such that a first electrical signal 210 generated by theamplifier 200 is saturated in the absence of the reagent card 106positioned between the optical signal source 150 and the optical signalgenerator 154. In the example shown, the voltage of the first electricalsignal 210 is approximately 5 V.

The substrate 135 may be translucent plastic that behaves as an opticaldiffuser, diffusing the optical signal between the optical signal source150 and the optical signal detector 154, for example. In response, theoptical signal detector 154 receives an optical signal which isrelatively weaker compared to the relatively strong signal received whenno reagent card 106 is present between the optical signal source 150 andthe optical signal detector 154. The optical signal detector 154 maygenerate a signal that is relatively weaker and indicative of therelatively weaker optical signal. The optical signal detector 154 maytransmit the signal to the amplifier 200 via the line 194. In responsethereto, the amplifier 200 generates a second electrical signal 212,which in the example shown in FIG. 7 has a voltage level between about 3and about 3.5 V.

Electrical signals generated by the amplifier 200, including the firstand second electrical signals 210 and 212 are provided to the cardcomparator circuit 202 via a line 216, and to the pad detector circuit204 via line 218. In general, the card comparator circuit 202 mayinclude analog and/or digital circuitry to form a comparator to comparethe magnitude of the electrical signals generated by the amplifier 200and a fixed or programmable reference voltage. In the example depictedin FIG. 6, a fixed reference voltage is provided to the card comparatorcircuit 202. The fixed reference voltage is selected to have a magnitudebetween the first electrical signal 210 and the second electrical signal212, e.g., between about 5 V and about 3.5 V. In this example, the fixedreference voltage is selected to be about 4.5 V such that the cardcomparator circuit 202 will detect the leading edge 136 of the substrate135. The output of the card comparator circuit 202 is provided to thecontroller 162 via the control line 196 and the controller 162 monitorsthe control line 196 to determine when the leading edge 136 of thesubstrate 135 enters the optical signal path 158.

As the reagent card 106 is further advanced along the travel surface110, a leading end 144 of a reagent pad 140 is positioned at leastpartially between the optical signal source 150 and the optical signaldetector 154 (e.g., in the optical signal path 158) and the reagent pad140 begins further interfering with the optical signal and causes afurther drop in the strength of the optical signal that reaches theoptical signal detector 154. The optical signal detector 154 detectsthis relatively weaker optical signal and generates an electrical signalindicative of the relatively weaker optical signal. The optical signaldetector 154 may transmit the electrical signal to the amplifier 200 ofthe optical detector interface 182. In response thereto, the amplifier200 generates a third electrical signal 220 as shown in FIG. 7.

The difference between the second electrical signal 212 and the thirdelectrical signal 220 may be very small, so the second electrical signal212 and the third electrical signal 220 may have an electrical offsetremoved, followed by amplification to amplify the difference between thesecond electrical signal 212 and the third electrical signal 220 inorder to aid the detection of the leading end 144 and the trailing end146 of the reagent pad 140 by the pad detector circuit 204.

In the embodiment depicted in FIG. 6, the pad detector circuit 204 isprovided with an offset removal circuit 230, a first amplifier circuit232, a pad comparator circuit 234, and a second amplifier circuit 236.The offset removal circuit 230 may be electrically coupled to the firstamplifier circuit 232 via a line 240. The first amplifier circuit 232may be electrically coupled to the pad comparator circuit 234 via a line242. The second amplifier circuit 236 may be electrically coupled to thepad comparator circuit 234 via a line 244.

In general, the offset removal circuit 230 is configured to remove afixed or programmable amount of voltage from the electrical signalsoutput by the amplifier 200 in order to increase the sensitivity of thepad detector circuit 204 as discussed above. The output of the offsetremoval circuit 230 is fed to the first amplifier circuit 232 via theline 240. The first amplifier circuit 232 receives the output of theoffset removal circuit 230 and serves to amplify the output of theoffset removal circuit 230. The amplified signal from the firstamplifier circuit 232 is provided to the pad comparator circuit 234 viathe line 242. And, a reference voltage generated by the second amplifiercircuit 236 is provided to the pad comparator circuit 234 via the line244.

The pad comparator circuit 234 receives the electrical signals via thelines 242 and 244 and compares the magnitudes of such signals in orderto generate a pad detect sensor signal 250 that is shown by way ofexample in FIG. 7. The pad detect sensor signal is provided to thecontroller 162 via the control line 198. The level of the referencesignal provided to the pad comparator circuit 234 from the secondamplifier circuit 236 may be controlled by the controller 162 using acontrol line 252.

In one embodiment, the offset removal circuit 230 is configured toremove 1.235 V from the electrical signals supplied by the amplifier200; the first amplifier circuit 232 is configured to amplify theelectrical signal from the offset removal circuit 230 by a factor of3.57; and the second amplifier circuit 236 is configured to amplify anelectrical signal from the controller 162 by a factor of 2.0, forexample. As will be understood by one skilled in the art, the parametersincluding the amount of offset, and the amplification factors used bythe first amplifier circuit 232 and the second amplifier circuit 236 canbe varied and/or calibrated based upon particular types of reagent cards106 to be processed by the analyzer 100. For example, the offset removalcircuit 230 may offset the incoming signals by subtracting the rangebelow the lowest measured signal from the received signal, andamplifying the resulting signal (e.g., about 2.5 times) to produce aprocessed signal indicative of the portion of a reagent card, if any,which is currently interfering with the optical signal or is positionedin the optical signal path 158.

The substantially exact position of the leading edge 136 of thesubstrate 135 of the reagent card 106, and of the leading ends 144 andthe trailing ends 146 of the reagents pads 140 may thus be detected, andthis information may be combined with the known location of the sampledispenser 174 to operate the card travel assembly 108 and/or the cardstripping assembly 120 to advance the reagent card 106 to substantiallycenter the reagent pad 140 under the sample dispenser 174 (e.g., on theline 176) by advancing the reagent card 106 a certain distance over thetravel surface 110, for example. Substantially centered should beunderstood to include the reagent pad 140 being centered over the line176, and to also include the reagent pad 140 being centered over theline 176 with a variance of between about 0 and about 30 percent of thewidth of the reagent pad 140, for example. Further, this information maybe combined with the known location of the imaging system 114 toposition one or more reagent pad 140 at a designated target location orarea along the travel surface 110 so that the imaging system 114 maytake one or more images or videos of one or more reagents pads 140, forexample.

Thus, the controller 162 receives a card detect sensor signal indicativeof an exact position of the leading edge 136 and the trailing edge 138of the substrate 135; as well as a pad detect sensor signal indicativeof the exact position of the leading end 144 and the trailing end 146 ofthe reagent pads 140 supported by the substrate 135. The controller 162may also correlate the information received from the card detect sensorsignal and the pad detect sensor signal with information from the cardtravel assembly 108. For example, when the card travel assembly 108includes a threaded mechanism for moving the reagent card 106, thecontroller 162 may count rotations of the threaded mechanism todetermine a number of turns of the threaded mechanism used for advancingthe reagent card 106 from the leading end 144 to the trailing end 146 ofthe reagent pads 140. For example, a waveform showing a signal 254 usedto monitor rotation of the threaded mechanism is shown in FIG. 7. In theexample shown, seven rotations of the threaded mechanism is used to movethe reagent card 106 from a first position where the leading end 144 iswithin the optical signal path 158 to a second position where thetrailing end 146 is within the optical signal path 158. This informationallows the controller 162 and the analyzer 100 to calculate anddetermine the width of a reagent pad 144 by measuring the distancebetween the leading end 144 and the trailing end 146 of the reagent pad140, for example.

The number of rotations for moving the reagent card 106 from the leadingend 144 to the trailing end 146 of the pad 140 can be used by thecontroller 162 to operate the mechanism of the card travel assembly 108that advances the reagent card 106 to substantially center the reagentpad 140 under the sample dispenser 174, or to move the reagent pad to adesignated location for the imaging system 114 to take an image of thereagent pad 140, for example.

As will be appreciated by persons of ordinary skill in the art, thestock from which the substrate 135 of a reagent card 106 is made mayvary its absorbance between about 99.90% and about 99.99%. Accordingly,a calibration of the strength or magnitude of the optical signal emittedby the optical signal source 150 may be performed by the optical sourceinterface 180 and/or the controller 162 with each new cassette 104 orwith each new batch of reagent cards 106, for example. In an exemplaryembodiment, the calibration may be performed by locating the edge 136 ofthe reagent card 106 as described above, and then advancing the reagentcard 106 a given distance through the optical signal path 158 so as toposition the reagent card 106 such that the optical signal path 158 ispositioned substantially between a first test strip 142 and a secondtest strip 142 (e.g., between a first reagent pad 140 and a secondreagent pad 140). The current provided to the optical signal source 150by the optical source interface 180 on the control line 186 may then bevaried, or adjusted, so that the electrical signal indicative of theoptical signal detected by the optical signal detector 154 does notsaturate the output of the amplifier 200, but has sufficient energy todetect the leading end 144 and the trailing end 146 of the reagent pad140. The strength or magnitude of the optical signal emitted by theoptical signal source 150 may be controlled by varying the amount ofcurrent supplied on the control line 186, for example, for the lot ofcard substrate 135. Thus, the calibration results in a desired level ofoptical signal to enable accurate detection thresholds.

Referring now to FIGS. 7-10, in operation, an analyzer 100 may functionas follows. A cartridge or cassette 104 including one or more reagentcards 106 may be loaded into the storage compartment 116, such as byopening the door 124, inserting the cassette 104 into the storagecompartment 116. The door 124 may be closed to secure the storagecompartment 116, for example.

The optical signal source 150 may be activated, such that the opticalsignal source 150 emits an optical signal, which optical signal may bedetected by the optical signal detector 154 as a first optical signal.As will be appreciated by a person of ordinary skill in the art, noreagent card 106 is positioned between the optical signal source 150 andthe optical signal detector 154 (e.g., in the optical signal path 158)at this stage. The optical signal detector 154 may detect the opticalsignal emitted by the optical signal source 150 and may generate a firstelectrical signal indicative of the detected first optical signal. Thefirst electrical signal may be transmitted to the optical detectorinterface 182 and may be processed by the controller 162 as describedabove with reference to FIGS. 6-7, for example.

The analyzer 100 may operate the card stripping assembly 120 to advancea reagent card 106 at least partially out of the cassette 104 andadvance the reagent card 106 towards the gate 128 (e.g., via the movableplate 132). As the leading edge 136 of the reagent card 106 is advancedand at least partially positioned between the optical signal source 150and the optical signal detector 154 (e.g., the leading edge 136 is atleast partially advanced in the optical signal path 158), the reagentcard 106 interferes with the optical signal detected by the opticalsignal detector 154, and as a result, the optical signal detector 154detects a second optical signal which is relatively weaker than thefirst optical signal, and generates a second electrical signalindicative of the second optical signal, for example. The secondelectrical signal may be transmitted to the optical detector interface182 and may be processed by the controller 162, for example

As the reagent card is further advanced towards the gate 128, thereagent card 106 may be advanced such that the leading end 144 of areagent pad 140 is positioned between the optical signal source 150 andthe optical signal detector 154 (e.g., the leading end 144 is at leastpartially positioned in the optical signal path 158) so that the pad 140interferes with the optical signal detected by the optical signaldetector 154, for example. The optical signal detector 154 may detect athird optical signal which is relatively weaker than the second opticalsignal described above, and may generate a third electrical signalindicative of the third optical signal, and transmit the thirdelectrical signal to the optical detector interface 182 or to thecontroller 162 as described above with reference to FIGS. 6-7, forexample.

The reagent card 106 may be advanced further by the card strippingassembly 120. If the reagent card 106 is the first reagent card 106 froma new lot and/or from a new cassette 104, the alignment system 122 maybe calibrated by calibrating the optical signal source 150 as describedabove, for example. The gate raising mechanism 130 may be activated oroperated by the analyzer 100 to at least partially raise the gate 128,so that the reagent card 106 may be advanced at least partially past thegate 128 and onto the travel surface 110, for example. For example, oneor more reagent pads 140, or test strips 142 may be advanced past thegate 128. The gate 128 may be lowered onto the reagent card 106, forexample, between adjacent reagent pads 140, as will be appreciated bypersons of ordinary skill in the art having the benefit of the instantdisclosure.

As the trailing end 146 of the reagent pad 140 is advanced through theoptical signal path 158 and out of the optical signal path 158, theoptical signal detected by the optical signal detector 154 may increase,and may become substantially equal to the second optical signal.Accordingly, the optical signal detector 154 may generate an electricalsignal which may be substantially similar or substantially identical tothe second electrical signal, and transmit such electrical signal to theoptical detector interface 182 as described above. As will beappreciated by persons of ordinary skill in the art the advancement ofsubsequent reagent pads 140 through the optical signal path 158 maycause the optical signal detector 154 to alternatively detect the secondoptical signal and the third optical signal, and to generate and outputcorresponding second electrical signal and third electrical signal tothe optical detector interface 182, for example. Further, as thetrailing edge 138 of the reagent card 106 is advanced through theoptical signal path 158, and before a leading edge 136 of a secondreagent card 106 is at least partially positioned in the optical signalpath 158, the optical signal detector 154 may detect the first opticalsignal, and may generate a signal substantially similar or equivalent tothe first electrical signal, and output such electrical signal to theoptical detector interface 182 as described above, for example.

As the reagent card 106 is at least partially advanced past the gate128, the card gripper 170 may engage the reagent card 106, such that thereagent card 106 may be advanced over the travel surface 110 by the cardtraveling assembly 108 via the card gripper 170.

The controller 162 may operate the card travel assembly 108 to advancethe reagent card 106 along the travel surface to a designated locationspaced at a first distance from the optical signal path 158. Forexample, the distance the reagent card 106 is advanced along the travelsurface 110 may be substantially equal to the first distance plus abouthalf the width of a reagent pad 140, when such width is known. Asanother example, the distance the reagent card 106 is advanced along thetravel surface 110 may be substantially equal to the first distance,plus about half the distance between the leading end 144 and thetrailing end 146 of a reagent pad 140 as determined by the controller162 as described above.

When the reagent card 106 is advanced over the travel surface 110 sothat one or more reagent pad 140 is substantially centered onto the line176 (including a variance of between about 0 and about 50 percent of thewidth of the reagent pad 140, (e.g. the distance between the leading end144 and the trailing end 146 of the reagent pad 140), a volume of samplemay be dispensed onto a central region of the one or more reagent pad140 by the sample dispenser 174 as shown in FIG. 10, for example. Thesubstantially exact position of the one or more reagent pad 140 may bedetermined by the controller 162 as described above. Further, theimaging system 114 may take one or more images of the one or morereagent pad 140 at any time after the volume of sample has beendispensed on the one or more reagent pad 140, and regardless of thelocation of the reagent card 106 on the travel surface 110, for example.In some exemplary embodiments, an image of the one or more reagent pad140 may be taken by the imaging system 114 concurrently with dispensingthe volume of sample on the one or more reagent pad 140, beforedispensing the volume of sample on the one or more reagent pad 140,immediately after dispensing the volume of sample on the one or morereagent pad 140, or at a preset time after the volume of sample isdispensed on the one or more reagent pad 140, and combinations thereof.In one exemplary embodiment, a video, or a sequence of images may betaken of the one or more reagent pad 140 as the one or more reagent pad140 is advanced along the travel surface 110 and as a volume of sampleis deposited on the one or more reagent pad 140.

In some exemplary embodiments, the imaging system 114 may take an image,a series of images, or a video, of the one or more reagent pad 140 asthe one or more reagent pad 140 is positioned on the line 176, or on adesignated target location or area (not shown) along the travel surface110.

When the reagent card 106 has been advanced along the travel surface 110by the card gripper 170 such that the trailing edge 138 of the reagentcard 106 is advanced past the imaging system 114, the reagent card 106may be removed from the travel surface 110 such as by being pushed offan edge of the travel surface 110 by the card gripper 170, and may bedisposed of in any desired manner, for example. The reagent card 106 maybe allowed to drop in a waste container (not shown), or may be manuallyremoved from the analyzer 100, or combinations thereof, for example.

Two or more reagent cards 106 may be moved through the analyzer 100 inthis or in similar manner. As needed or desired, a replacement cassette104 may be inserted into the storage compartment 116 as the previouscassette 104 is emptied of the reagent cards 106 contained therein, oras different reagents cards 106 are indicated for sample analysisconducted by the analyzer 100, and combinations thereof, for example. Acalibration procedure may be run with each new cassette 104 as describedabove.

While the inventive concepts disclosed herein have been described inconnection with the exemplary embodiments of the various figures, theyare not limited thereto and it is to be understood that other similarembodiments may be used or modifications and additions may be made tothe described embodiments for performing the same function of theinventive concepts disclosed herein without deviating therefrom.Therefore, the inventive concepts disclosed herein should not be limitedto any single embodiment, but rather should be construed in breadth andscope in accordance with the appended claims. Also, the appended claimsshould be construed to include other variants and embodiments of theinventive concepts disclosed herein, which may be made by those skilledin the art without departing from the true spirit and scope thereof.

From the above description, it is clear that the inventive conceptsdisclosed herein are well adapted to carry out the objects and to attainthe advantages mentioned herein as well as those inherent in theinventive concepts disclosed herein. While exemplary embodiments of theinventive concepts disclosed herein have been described for purposes ofthis disclosure, it will be understood that numerous changes may be madewhich will readily suggest themselves to those skilled in the art andwhich are accomplished within the scope of the inventive conceptsdisclosed and as defined in the appended claims.

1. A method, comprising: passing a reagent card having a substrate, anda reagent pad through an optical signal path between an optical signalsource and an optical signal detector, the optical signal source and theoptical signal detector being spaced apart, the reagent pad including aleading end and a trailing end; receiving a first electrical signal fromthe optical signal detector by an optical detector interface coupled tothe optical signal detector and configured to receive signals from theoptical signal detector, the first electrical signal being indicative ofthe substrate interfering with the optical signal; receiving a secondelectrical signal being indicative of the substrate and reagent pad ofthe reagent card interfering with the optical signal; detecting atransition between the first electrical signal and the second electricalsignal as the reagent card is moved through the optical signal path; andoutputting a pad detect signal responsive to detection of thetransition, the pad detect signal being indicative of a position of atleast one of the leading end and the trailing end of the reagent pad. 2.The method of claim 1, wherein the optical signal path is at a firstlocation, and further comprising: receiving the pad detect signal by acontroller; activating a card moving mechanism to move the reagent cardto a second location; and dispensing a volume of a sample at the secondlocation onto the reagent pad.
 3. The method of claim 2, wherein thereagent pad has a central region, and wherein dispensing is definedfurther as dispensing the volume of the sample on the central region ofthe reagent pad.
 4. The method of claim 2, further comprising moving thereagent pad to a third location, and reading the reagent pad at thethird location, wherein reading the reagent pad comprises capturing animage of the reagent pad at the third location.
 5. The method of claim1, wherein the reagent card is a multiple profile reagent card having amatrix of reagent pads.
 6. The method of claim 1, wherein the substrateis translucent plastic.
 7. A method, comprising: passing a reagent cardhaving a substrate, and a reagent pad through an optical signal pathbetween an optical signal source and an optical signal detector, theoptical signal source and the optical signal detector being spacedapart, the reagent pad including a leading end and a trailing end, thesubstrate being constructed of a material that behaves as an opticaldiffuser, the optical signal path being at a first location; receiving afirst electrical signal from the optical signal detector by an opticaldetector interface coupled to the optical signal detector and configuredto receive signals from the optical signal detector, the firstelectrical signal being indicative of the substrate interfering with theoptical signal; receiving a second electrical signal being indicative ofthe substrate and reagent pad of the reagent card interfering with theoptical signal; detecting a transition between the first electricalsignal and the second electrical signal to determine a substantiallyexact position of at least one of the leading end and the trailing endof the reagent pad; moving the reagent pad to a known second locationupon determining the substantially exact position of at least one of theleading end and the trailing end of the reagent pad; and dispensing asample onto the reagent pad by a sample dispenser, at the secondlocation.
 8. The method of claim 7, wherein moving the reagent pad tothe known second location is defined further as: receiving a pad detectsignal by a controller; and activating a card moving mechanism to movethe reagent card to the second location.
 9. The method of claim 7,wherein the reagent pad has a central region, and wherein dispensing isdefined further as dispensing the volume of the sample on the centralregion of the reagent pad.
 10. The method of claim 7, further comprisingmoving the reagent pad to a third location, and reading the reagent padat the third location, wherein reading the reagent pad comprisescapturing an image of the reagent pad at the third location.
 11. Themethod of claim 7, wherein the optical signal has a wavelength of about850 nanometers.
 12. The method of claim 7, wherein the optical signalsource includes a vertical cavity surface emitting laser.
 13. The methodof claim 12, wherein the vertical cavity surface emitting laser isconfigured to transmit an optical signal including a beam having anangular spread of less than about 2°.
 14. A method, comprising: passinga reagent card having a substrate, and a reagent pad through an opticalsignal path between an optical signal source and an optical signaldetector, the optical signal source and the optical signal detectorbeing spaced apart, the reagent pad including a leading end and atrailing end, the substrate being constructed of a material that behavesas an optical diffuser, the optical signal path being at a firstlocation; detecting a transition between a first electrical signal and asecond electrical signal to determine a substantially exact position ofat least one of the leading end and the trailing end of the reagent pad,the first electrical signal being indicative of the substrateinterfering with the optical signal, the second electrical signal beingindicative of the substrate and reagent pad of the reagent cardinterfering with the optical signal; moving the reagent pad to a knownsecond location upon determining the substantially exact position of atleast one of the leading end and the trailing end of the reagent pad;and dispensing a sample onto the reagent pad by a sample dispenser, atthe second location.
 15. The method of claim 14, wherein moving thereagent pad to the known second location is defined further as:receiving a pad detect signal by a controller; and activating a cardmoving mechanism to move the reagent card to the second location. 16.The method of claim 14, wherein the reagent pad has a central region,and wherein dispensing is defined further as dispensing the volume ofthe sample on the central region of the reagent pad.
 17. The method ofclaim 14, further comprising moving the reagent pad to a third location,and reading the reagent pad at the third location, wherein reading thereagent pad comprises capturing an image of the reagent pad at the thirdlocation.
 18. The method of claim 14, wherein the optical signal has awavelength of about 850 nanometers.
 19. The method of claim 14, whereinthe optical signal source includes a vertical cavity surface emittinglaser.
 20. The method of claim 19, wherein the vertical cavity surfaceemitting laser is configured to transmit an optical signal including abeam having an angular spread of less than about 2°.